Process for making half-tone cuts.



MAROELLUS O. COOHRAN, OI COTTAGE GROVE, OE EGON.

PROCESS FOR .MAKING HALF-TONE CUTSI Specification of Letters Extent.

Patented Feb. 11, 1908.

Application filed January 26.1907. fierizd No. 354.226-

To all whom it may concern:

Be it known that l, MARImLLUs C. Cocn- RAN, a citizen of the United. States, residing at Cottage Grove, county of Lane, and State I of Oregon, have invented certain new and I useful lm rovements in Processes for Malelng Hall one Cuts, of which the following is a specification.

My invention relates to 111 half-tone cuts.

The ob ect of the present invention is the processes for makpr ovision of a process whereby lmll-trme cuts may be rapidly, inexpensively, and

easily made and the plate orlihn which has can prepared by the process may be used to direct y print on the paper.

In carrying out my new process, first expose any ordinary dry plate through a screen and the picture or design. The plate is developed and treated es any photographic ne etive.

eeond; take a plate of glass, wood, him, or metal, which is provided with the usual emulsion as on ordinary photographic plates expose itto the light tirough the negative already made.

Third; the plate is then treated to a bath, in the followingproportions. Water, lire ounces. Carbonate oi soda,one halt ounce.

Pyrogellic acid, thirty grains. ()xolt-ic acid, two grains;

Fourth; then treat to the following bath for the period of five minutes. in pro vortion, Water, sixty four ounces. Uyanic of potassium, three ounces. Uhlorid of silver, one fourth ounce.

Fifth; dry the plate at, one hundred and ten degrees, Fahrenheit, and the cut is ready to mount for use.

l l l l l l l The chemical react-ions with the emulsion of the plate or lilm such that the emulsion is solidified and the shadows raised so that the plate or film will receive ink and print as an ordinary half-tone. Alter treatment of the lilni or plate by the chemical baths as aforesaid, and dried said .lilm. or plate is mounted on u wood base and is ready for use in the printing press to print direct on the paper.

With my process the plate or lilm itself serves as the out and may be prepared ready [or use in the press within thirty minutes after the plate or lilm has been exposed in the owners, thereby saving :1 very great amount ol time horotol'me lost in making hall-tone (:uts beside reducing the cost to only a few cents.

llavingr thus described my invention, what I claim as new uud desire to secure by-Lotters Patent, is

The process 01 making hall-tone cuts consisting in inking 2t photographic impression on an ordinary emulsionized photographic film, plate 01' other substance, and thereafter subjecting said negative to successive baths, tho lirst consisting 01 water, .:arbouate of soda, sullite ol' soda, pyrogallic acid and oxoltio acid, and the second consisting of water, eyenid of potassium, and chlorid of silver, to thereby solidify the emulsion and raise the shadows of the negative.

in testimony whereof, I hereunto allix my signature in presence oi two Witnesses.

MARCELLUS C. COCHRAN.

WVitnesses JEROME Knox, REN SANFORD. 

